Variations in patterns of follicle development in prolific breeds of sheep

Driancourt, Marc Antoine; Gauld, I. K.; Terqui, M.; Webb, Robert I.

doi:10.1530/jrf.0.0780565

Cited by 50 publications

(34 citation statements)

References 11 publications

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“…A large proportion of follicles marked at luteolysis (Day 0) became atretic by ovulation time and were replaced by smaller follicles starting to grow later in the follicular phase. Rate of atresia between Days 0 and 2 among marked follicles was lower in Finn than in B-crossed ewes, as previously shown by Driancourt et al (1986). However, although more large marked follicles increased in size, the proportion that reached ovulation was similar to that observed for B-crossed females.…”

Section: Discussionsupporting

confidence: 84%

“…The absence of corre¬ lation between ovulation rate and the total follicular population was also observed many times both in between-and within-breed comparison (Romanov vs Ile-de-France: Driancourt et al, 1986; Finn selected for high vä low ovulation rate: Driancourt et al, 1990).…”

Section: Discussionmentioning

confidence: 75%

“…These factors are most probably involved in the recruitment process that determines a group of follicles capable of ovulating and/or in the selection process during which a follicle is chosen to ovulate. However, the different patterns by which prolific breeds of sheep could achieve higher ovulation rates (Driancourt et al, 1986) highlight the complexity of terminal follicular growth. Romanov ewes have a large number of follicles recruited and a rate of follicular loss through atresia similar to Ile-de-France (non-prolific control) ewes, whereas Finn ewes have similar numbers of recruitable follicles but reduced atresia compared to Finn Blackface ewes of lower prolificacy (Driancourt et al, 1986).…”

Section: Introductionmentioning

confidence: 99%

“…However, the different patterns by which prolific breeds of sheep could achieve higher ovulation rates (Driancourt et al, 1986) highlight the complexity of terminal follicular growth. Romanov ewes have a large number of follicles recruited and a rate of follicular loss through atresia similar to Ile-de-France (non-prolific control) ewes, whereas Finn ewes have similar numbers of recruitable follicles but reduced atresia compared to Finn Blackface ewes of lower prolificacy (Driancourt et al, 1986). In Booroola ewes, higher ovulation rate is reached by con¬ tinuous recruitment during the follicular phase, a reduced amount of atresia and the ability of mature follicles to wait for ovulation (Driancourt et al, 1985a).…”

Section: Introductionmentioning

confidence: 99%

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Follicular dynamics and dominance in Booroola x Finnish Landrace and Booroola x Suffolk ewes heterozygous for the F gene

Castonguay¹,

Dufour²,

Minvielle³

et al. 1990

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Summary. To Group 3, the proportion of marked follicles that ovulated was higher for S ewes than in those of the prolific genotypes. The number of follicles not marked at Day 0 but ovulating (compared to the total number of ovulations) was higher in BFL, BS and FL (8/11, 9/13 and 9/13) than S (3/10) ewes. In Exp. 2, prolific (BFL + BS) and non-prolific (S) ewes were compared following destruction of follicles \m=ge\3mmwith the F1 left intact (Treatment 1) or destroyed (Treatment 2), 12 days after sponge insertion. At 4 days after treatment (at sponge removal), the numbers of 3\p=n-\4mm follicles were not different between the 2 treatments and a very high proportion of the F1 follicles left intact at Day 0 had regressed at Day 4 in both genotypes. From these results, it can be concluded that the higher ovulation rate in Booroola-crossed ewes is not associated with a higher number of recruitable follicles but involves late follicular-phase recruitment and selection combined with smaller preovulatory follicle diameters. Dominance by the largest follicle is not present in ewes of prolific or non-prolific genotypes. In contrast, it is likely that small sized follicles exert a negative effect on growth of large follicles.

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Section: Discussionsupporting

confidence: 84%

Section: Discussionmentioning

confidence: 75%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Follicular dynamics and dominance in Booroola x Finnish Landrace and Booroola x Suffolk ewes heterozygous for the F gene

Castonguay¹,

Dufour²,

Minvielle³

et al. 1990

Reproduction

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“…As diferenças raciais na resposta superovulatória provavelmente são explicadas por variação no crescimento folicular, entre as raças, em resposta ao FSH exógeno (Ammoun et al, 2006). Tais diferenças podem estar relacionadas com a expressão mais elevada ou com maior sensibilidade dos receptores de FSH no ovário (Driancourt et al, 1986;Dufour et al, 2000).…”

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